Study of the Effects of Iron on Lung Blood Pressure at High Altitude
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Purpose
Body iron levels may be important in determining how the blood pressure in the lungs changes in response to low oxygen levels. At high altitude, where oxygen levels are low, some patients develop elevated lung blood pressure. The investigators hypothesize that, in high altitude residents with elevated lung blood pressure, iron supplementation will cause a reduction in lung blood pressure.
| Condition | Intervention | Phase |
|---|---|---|
|
Hypertension, Pulmonary |
Drug: Iron sucrose Drug: Normal saline |
Phase 2 |
| Study Type: | Interventional |
| Study Design: | Allocation: Randomized Endpoint Classification: Efficacy Study Intervention Model: Parallel Assignment Masking: Double Blind (Subject, Investigator) Primary Purpose: Treatment |
| Official Title: | Study of the Effects of Iron Supplementation on High Altitude Pulmonary Hypertension. |
- Change in pulmonary artery systolic pressure [ Time Frame: 28 days ] [ Designated as safety issue: No ]
| Estimated Enrollment: | 26 |
| Study Start Date: | August 2009 |
| Estimated Primary Completion Date: | October 2009 (Final data collection date for primary outcome measure) |
| Arms | Assigned Interventions |
|---|---|
|
Experimental: Iron group
Patients with high altitude pulmonary hypertension receive six intravenous infusions of iron sucrose, administered on days 0, 4, 8, 12, 16 and 20 of the study. The total study period is 28 days. Pulmonary artery systolic pressure is measured before each infusion, and again on day 28.
|
Drug: Iron sucrose
An intravenous infusion of 100 mg of iron is administered on days 0, 4, 8, 12, 16 and 20 of the study, giving a total of six iron infusions for each participant in the iron group over the course of the 28-day study period.
Other Name: Venofer (iron sucrose)
|
|
Placebo Comparator: Saline group
Patients with high altitude pulmonary hypertension receive six intravenous infusions of normal saline, administered on days 0, 4, 8, 12, 16 and 20 of the study. The total study period is 28 days. Pulmonary artery systolic pressure is measured before each infusion, and again on day 28.
|
Drug: Normal saline
An intravenous infusion of 100 ml of normal (0.9 %) saline is administered on days 0, 4, 8, 12, 16 and 20 of the study, giving a total of six saline (placebo) infusions for each participant in the saline group over the course of the 28-day study period.
|
Detailed Description:
Pulmonary hypertensive disorders frequently complicate hypoxic lung disease and worsen patient survival.
Hypoxia-induced pulmonary hypertension is also a major cause of morbidity at high altitude. Hypoxia causes pulmonary hypertension through hypoxic pulmonary vasoconstriction and vascular remodelling. These processes are thought to be regulated at least in part by the hypoxia-inducible factor (HIF) family of transcription factors, which coordinate intracellular responses to hypoxia throughout the body.
HIF is regulated through a cellular degradation process that requires iron as an obligate cofactor. In cultured cells HIF degradation is inhibited by reduced iron availability (by chelation with desferrioxamine) and potentiated by iron supplementation. In humans, laboratory experiments lasting eight hours have shown that acute iron supplementation blunts the pulmonary vascular response to hypoxia, while acute iron chelation with desferrioxamine enhances the response.
These findings suggest that iron may also affect the pulmonary vascular response to hypoxia over longer time periods. The purpose of this study, which will take place at high altitude in Kyrgyzstan, is to investigate whether iron supplementation can reduce pulmonary artery pressure in patients with established high altitude pulmonary hypertension.
Eligibility| Ages Eligible for Study: | 18 Years and older |
| Genders Eligible for Study: | Both |
| Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- High altitude natives, currently resident at high altitude
- Pulmonary hypertension (mean pulmonary artery pressure > 25 mmHg)
- Pulmonary artery systolic pressure measurable using Doppler echocardiography
Exclusion Criteria:
- Clinical evidence or history of major co-morbidity
- Recent changes to relevant medications, or taking iron/vitamin supplements
Contacts and Locations| Kyrgyzstan | |
| Institute of Molecular Biology and Medicine | |
| Bishkek, Kyrgyzstan, 720040 | |
| Principal Investigator: | Peter A Robbins, DPhil BM BCh | University of Oxford |
More Information
No publications provided
| Responsible Party: | Professor Peter Robbins, Professor of Physiology, University of Oxford |
| ClinicalTrials.gov Identifier: | NCT00960921 History of Changes |
| Other Study ID Numbers: | Oxford-Kyrgyzstan-2009 |
| Study First Received: | August 17, 2009 |
| Last Updated: | April 1, 2011 |
| Health Authority: | United Kingdom: Research Ethics Committee Kyrgyzstan: Ethics Committee |
Keywords provided by University of Oxford:
|
Pulmonary artery pressure Hypoxia Iron Hypoxia-inducible factor High altitude |
Additional relevant MeSH terms:
|
Hypertension Hypertension, Pulmonary Altitude Sickness Vascular Diseases Cardiovascular Diseases Lung Diseases Respiratory Tract Diseases Respiration Disorders Ferric oxide, saccharated Ferric Compounds |
Iron Hematinics Hematologic Agents Therapeutic Uses Pharmacologic Actions Trace Elements Micronutrients Growth Substances Physiological Effects of Drugs |
ClinicalTrials.gov processed this record on May 21, 2013